This invention generally relates to a dental prosthesis, and in particular to improvements in articles used in the manufacture of a dental prosthesis, components thereof, and methods for manufacturing such articles and components.
More particularly this invention relates to a dental prosthesis of the type utilizing an implant member, having a threaded bore, which is adapted to be surgically placed beneath gum tissue and into underlying bone structure. Conventionally, there is provided a straight prosthesis support having a threaded portion at its lower end and a post at its upper end. The threaded portion of the straight prosthesis support is sized so that it can be threaded into the surgically placed implant member. The post thus extends into the mouth and serves as a supporting structure for a dental prosthesis such as a crown or bridge.
Unfortunately, straight prosthesis support structures of the type described suffer from certain drawbacks and deficiencies. For example, if the implant member, when surgically placed, is not precisely oriented relative to the mouth and gums, the post at the upper end of the support structure will extend crookedly into the mouth when the threaded portion is screwed into the implant member. This, in turn, typically results in a poorly-fitting, misaligned, or otherwise esthetically or functionally deficient prosthesis. Often such a prosthesis must be replaced or refitted, resulting in considerable discomfort, inconvenience and expense for the patient.
Moreover, even when the implant member is precisely oriented, so that the post extends straight into the mouth when the threaded portion of the support structure is screwed into the implant member, a poorly-fitting or misaligned prosthesis may result. This is due to the fact that often times a proper-fitting prosthesis requires that the post extend into the mouth at a specific angle, depending on the geometry of the patient's mouth and teeth.
In an effort to overcome problems of the type described, there has been developed support structure comprising a base member and separate post member. The base member typically has a lower threaded section, an intermediate flange section and an upper extension section. The intermediate flange section may be characterized by a hexagonal seat for orienting the separate post member in any one of several directions.
The separate post member typically has a lower angled section and an upper prosthesis supporting section. The lower angled section conventionally defines a bore which extends obliquely from the bottom surface through a side surface of the angled section. The opening in the bottom surface may be twelve-pointed, and sized to fit over the hexagonal seat in the flange portion of the base member in any one of multiple positions.
In application, the threaded section of the base member is screwed into the implant member with the upper extension section extending into the mouth. The opening in the bottom surface of the angled section is then fitted over the upper extension section and seated onto the hexagonal seat in the flange section of the base member. The orientation of the angled section, and hence the orientation of the upper supporting section, can thus be adjusted to any one of the numerous positions defined by the twelve-pointed opening. This gives the dental professional many alternatives in trying to fabricate a dental prosthesis that will fit properly in the mouth. Moreover, by making several different angled sections, each such section having a bore that extends at a different oblique angle through the bottom surface, the dental professional is afforded substantial flexibility in installing a supporting structure for a dental prosthesis which extends into the mouth at the proper orientation in an effort to provide a proper fit.
Though the system described above, utilizing a base member and separate post member, has been successfully used, it too is not without certain inherent deficiencies. First, even though the twelve-pointed opening, along with the variety of available angled sections, afford substantial flexibility in fabricating a supporting structure for a dental prosthesis, the angles and orientations so afforded are nonetheless limited. Moreover, after the angled section of the post member has been fitted over the extension section of the base member, the extension member typically extends so far through the side surface of the angled section that its end must be severed by the dental professional. Thus, this system entails substantial additional effort on the part of the dental professional, and still does not ensure a custom fit in view of the finite angles and orientations that can be achieved.
It is thus a primary object of this invention to provide improved articles utilized in manufacturing a dental prosthesis, along with improved components therefor. It is also an object of this invention to provide an improved method for manufacturing such articles and components. It is a further object of this invention to provide such articles and components which permit a wider variety of angles and positions for a support member for a dental prosthesis than have ordinarily been available heretofore.